Apparatus and method for handling concrete blocks



Feb. 11, 1969 H. N. SHUTE 3,427,009

APPARATUS AND METHOD FOR HANDLING CONCRETE BLOCKS Filed Oct. 21, 1966Sheet 0114 F|Gl T" as 35 M/ VEN TOR HARRY NORMAN SHUTE BY mw a ATTORNEYS Feb. 11, 1969 SHUTE 3,427,009

APPARATUS AND METHOD FOR HANDLING CONCRETE BLOCKS Filed Oct. 21, 1966Sheet 2 of 4 'VTTVTT AJL TI T

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APPARATUS AND METHOD FOR HANDLI\NG CONCRETE BLOCKS Filed Oct. 21, 19661969 H. N. SHUTE APPARATUS AND METHOD FOR HANDLING CONCRETE BLOCKS FiledOct. 21, 1966 Sheet FIG-1O United States Patent 3,427,009 APPARATUS ANDMETHOD FOR HANDLING CONCRETE BLOCKS Harry Norman Shute, Shute ConcreteProducts, Inc., 4810 Woodside Drive, Richmond, Ind. 47274 Filed Oct. 21,1966, Ser. No. 588,559 US. Cl. 26328 20 Claims Int. Cl. F27b 3/12, 9/00;B281) /00 ABSTRACT OF THE DISCLOSURE Racks of concrete blocks aredelivered from a rack loading station to an open top steam curing kilnand are arranged in horizontally spaced relation with a cover for thekiln being formed by a plurality of substantially rigid panels arrangedin a coplanar relation. After the blocks on each rack are cured, therack is lifted from the kiln and delivered to a rack unloading station,after which the blocks are arranged in the form of cubes which aredelivered to a storage rack and arranged in tiers on gravity feed rollerconveyors.

This invention relates to the production of concrete blocks, and moreparticularly, to an improved method and apparatus for efiicientlyhandling and curing concrete blocks with reduced labor and equipmentcosts so as to produce blocks at a minimum unit cost. The term concreteblocks as used herein is intended to include all forms of concretemodules which are adapted to be used as structural or decorative membersof a building or other structure.

Concrete blocks are commonly produced by an automatic block machinewhich forms batches of blocks on steel pallets which are successivelysupplied to the ma chine. The pallets of fresh concrete blocks areloaded into a series of racks by an automatic loading machine and eachloaded rack is then transported, commonly by a power operated fork-lifttruck, to a tunnel-like kiln through an open end of the kiln. After thekiln is filled, it is closed usually by a hinged door and steam isintroduced for providing a hot, humid atmosphere for a period of severalhours to cure the blocks.

After the curing operation, the kiln is opened, and each rack of blocksis transported, such as by a fork-lift truck, from the kiln to automaticunloading equipment which removes each pallet of cured blocks from therack. The blocks are then processed through a separating machine whereeach batch of block is removed or separated from its supporting steelpallet and the pallets are successively returned to the block machinefor use in forming new blocks.

After the cured concrete blocks are separated from the steel pallets,the blocks are usually transferred by a conveyor to a cubing machinewhich automatically collects and stacks a predetermined number of blocksto form a large cube. The cube is subsequently transported to a storagearea or yard, again usually by a fork-lift truck which either engages awooden pallet supporting the cube or the bottom layer of blocks in thecube.

It has been found that considerable investment is required in theconstruction of the tunnel-like kilns and in the fork-lift trucks whichare used to transport the racks to and from the kilns and intransporting the palletized cubes to the storage yard. In addition, ithas been found that the labor cost for the truck operators is asignificant cost and, of course, these costs are reflected in theselling price of the blocks.

Accordingly, it is a primary object of the present invention to providean improved method and apparatus "Ice for handling and curing concreteblocks to minimize the cost in producing the blocks.

It is also an object of the invention to provide novel apparatus whichis adapted for providing automatic or semi-automatic transfer orprocessing of the blocks to and from the curing kiln and to the storageyard.

Another object of the invention is to provide apparatus including anovel curing kiln having an open top for receiving a substantial numberof curing racks, and further including an overhead crane system formoving each rack from the rack loading machine to the kiln and then tothe rack unloading machine.

Still another object of the invention is to provide apparatus asoutlined in the preceding paragraph wherein each rack carries a covermember which cooperates with the cover member of adjacent racks when theracks are within the kiln to form an overall top cover for the kiln.

It is also an object of the invention to provide apparatus as outlinedabove and including sealing means for preventing the escape of steamfrom the kiln between the cover members on the racks during curing ofthe blocks.

Still another object of the invention is to provide apparatus includinga novel storage rack and means for automatically transferring andloading palletized cubes of cured blocks into the storage rack.

Other objects and advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

In the drawings- FIG. 1 is a somewhat diagrammatic plan view ofapparatus constructed in accordance with the invention and showing acuring kiln also constructed in accordance with the invention;

FIG. 2 is a vertical section through the kiln as taken generally alongthe line 22 of FIG. 1;

FIG. 3 is a perspective view of a typical guide member for maintaininguniform orientation of the block supporting racks within the kiln;

FIG. 4 is a fragmentary section of a portion of a loaded kiln as takengenerally along the line 4 4 of FIG. 1;

FIG. 5 is a plan view of the kiln with the racks removed and showingdiagrammatically the means for producing steam and venting eachcompartment of the kiln;

FIG. 6 is a section of a steam generating trough as taken generallyalong the line 66 of FIG. 5;

FIG. 7 is a fragmentary section of adjacent cover members and showingmeans for forming a vapor seal therebetween;

FIG. 8 is a perspective view of a typical rack removed from the kiln andshowing two pallets of blocks supported thereby;

FIG. 9 is a perspective view of a storage rack and as sociated loadingequipment constructed and arranged in accordance with the invention;

FIG. 10 is an end elevational view of the storage rack and loadingequipment shown in FIG. 9; and

FIG. 11 is a perspective view of a modified form of the apparatus of theinvention.

Referring to the drawings which illustrate preferred embodiments of theinvention, FIG. 1 shows an automatic block forming machine 15 whichsuccessively forms batches of blocks B (FIG. 2) on successively suppliedsteel plate-like pallets 16. The pallets of blocks are conveyed from theblock machine 15 to an automatic racking machine 18 which loads thepallets 16 into racks 20 (FIG. 8) at difierent elevations or tiersformed by angle support members 21 extending laterally between legs 22rigidly connected by upper longitudinal members 23.

Each rack 20 includes a cover member 25 which preferably is formed froma rigid insulated water and steam proof material, as for example, alaminated sheet manufactured by Johns-Manville and including aninsulation core 26 (FIG. 7) spaced between a pair of rigid asbestossheets 27. Surrounding each cover member 25 is a resilient seal 28including a flexible casing 29 covering a resilient sponge-like material31. The casing 29 is secured to the sheets 27 by a series of top andbottom screws 32. The racks 20 also include hanger or support rods 34which extend through the cover member 25 and are rigidly secured to theend support legs 22.

The racks 20 are normally stored in a pit-like kiln 35 (FIGS. 1, Z andwhich includes side walls 36 adjoining end walls 37 and intermediatewalls 38 which divide the kiln into compartments 40 each having an opentop. The open top is preferably at or near ground level, although theentire kiln of this invention may be placed above ground level. Thewalls 36, 37 and 38 of the kiln are preferably constructed on concreteblocks and are supported by a poured concrete floor 41 in which areformed series of parallel, spaced rectangular troughs 42 extendingbetween the side walls 36 with one or more troughs in each compartment40. A layer 43 of insulating material, as for example, polyurethaneboard is provided adjacent the outer surface of the walls 36 and 37 anda corresponding layer 44 is provided under the floor 41 to minimize thetransfer of heat from the kiln into the surrounding earth. For purposesof illustration, each compartment 40' of the kiln 35 is sufficientlylarge to enclose a group of racks 20 (FIG. 1). As shown in FIG. '2, thelifting racks 20 each have a height which corresponds substantially tothe vertical depth of the kiln 35.

An air inlet manifold 45 (FIGS. 2 and 5) extends longitudinally alongone side wall 36 of the open top kiln 35 and connects with upper andlower inlet ducts 47 for supplying air to each compartment 40 of thekiln from a blower 48. A corresponding exhaust manifold 50 extendslongitudinally along the opposite side wall 36 and is connected to eachcompartment 40 of the kiln by upper and lower ducts 51 for venting orexhausting air supplied through the inlet ducts 47. A remotelycontrollable valve member or damper 52 is provided in each of the ducts47 and 51 for controlling the flow of air through each compartment 40 ofthe kiln 35.

A series of guide members 55 (FIGS. 2 and 3) each having taperedsurfaces 56, are mounted on the floor 41 within each compartment 40 ofthe kiln 35 for receiving the corner legs 22 of the racks 20. The guidemembers 55 cooperate in maintaining uniformly aligned relationshipbetween adjacent racks 20 with the abutting seals 28 in uniform pressurecontact so that when the racks 20 are in place in the kiln the covermembers 25 cooperate with the walls 36, 37 and 38 to form a relativelyair tight and steam impervious insulating top cover for each compartmentof the kiln. The individual cover members 25 thus align into coplanarrelation over the kiln section forming a relatively rigid surface onwhich an operator may safely walk, if necessary.

A V-shaped metal trough 58 (FIG. 6) having end walls 59 is mountedwithin each of the rectangular concrete troughs 42 formed within thefloor 41. A conduit 60 (FIGS. 5 and 6) extends longitudinally withineach trough 58 from a main supply line 61. Low pressure steam, hot oil,or other heated fluid is circulated within each conduit 60 for heating apredetermined quantity of water 62 supplied to the corresponding trough58 to produce vapor or steam in each compartment 40' of the kiln duringthe curing operation.

For transporting each of the racks 20 between the kiln 35 and theracking machine 18, the apparatus of the invention includes a bridgecrane 65 (FIGS. 1 and 11) including a pair of parallel extending rails66 (FIG. 11) which are connected by laterally extending members 67supported by wheels 68 which roll on parallel spaced tracks 69 extendingparallel to the side walls 36 of the kiln 35. Preferably the wheels 68are driven by a motor 70 (FIG. 11).

A trolley or carriage 72 is supported by the rails 66 for traversingmovement between the tracks 69 and is powered by a motor 73. Thecarriage 72 supports a vertically extendable frame 75 which is poweredby a motor 76 and carries clamping or grab hooks (not shown) forgripping the hanger rods 34 on each rack 20. As shown in FIG. 1, thebridge crane 65 not only travels over the entire kiln 35 but alsotravels over the racking machine 18 so that each rack 20 can be liftedfrom the kiln 35 and transported to the racking machine 18 for loadingthe pallets of new blocks B into the racks.

After the blocks are cured within the kiln, each rack 20 is lifted bythe overhead crane 65 from the kiln 35 and transported back to theracking machine 18 where the pallets 16 of cured blocks areautomatically unloaded from the racks and are then transported to aseparating machine 80 where the blocks are removed from the pallets 16.The pallets are then transported by a conveyor 81 back to the blockmachine 18 to be reused for forming blocks.

The conveyor 82 transports successive rows of blocks from the separatingmachine 80 to a cubing machine 85 which stacks several layers of blocksonto a wooden pallet '87 (FIG. 9) to form a cube C. A typical cube C mayinclude various numbers of blocks depending upon the size of the blocks.Each pallet 87 of blocks is deposited by the cubing machine on aself-propelled platform car 88 (FIG. 9) having front wheels 89straddling an endless rail 90.

The endless rail 90 extends from the cubing machine 85 to the receivingside of a storage rack and then back to the cubing machine. The storagerack 95 is constructed with a series of parallel spaced vertical posts96 connected at the top by cross members 97. A series of rollers 98 aremounted on each of the posts 96 and cooperate with corresponding rollerson adjacent posts to form several tiers within the rack. The rollers 98defining each tier are arranged in sloping relationship as shown in FIG.10. Preferably the storage rack is intended to be under cover, however,the rack may be installed outside a building.

Extending above the track 90 adjacent the receiving side of the storagerack 95 is a bridge crane 100 which includes parallel spaced tracks 102supported by wheels (not shown) mounted on laterally extending tracks inthe same manner as the bridge crane 65. A trolley or carriage 104powered by a motor 105, is supported by the rails 102 for traversingmovement across the receiving side of the rack. A vertically extendableframe 106 is suspended from the carriage 104 and supports parallelspaced fork members .107.

As each platform car 88 carrying a palletized cube of blocks approachesthe storage rack 98, the fork members 107 are inserted into the pallet87 and the cube of blocks is lifted from the car and elevated to one ofthe storage tiers within the storage rack 95 as shown in FIG. 10. Theframe 106 is then rotated 90 after which the crane moves toward thestorage rack and the fork members 107 deposit the cube of blocks on therollers 98 so that the pallet of blocks move by gravity towards thedischarge side of the rack. After each pallet of blocks is removed froma platform car 88, the car automatically continues on the endless track90 to the cubing machine 85 for receiving another palletized cube ofblocks.

Referring to FIG. 11, which shows a modified form of apparatusconstructed in accordance with the invention, the vertically extendableframe 75 of the bridge crane 65 supports a rectangular frame 110 fromwhich depends a series of pivotally mounted arms 112 each having ahooked shape lower end portion 113. The arms 112 are simultaneouslyopened and closed by corresponding links 1'14 which connect the arms toeccentric locations on corresponding actuating disks 115 rotatablydriven by a reversible motor 116. Each cover member 25' of the racks 20'is formed with spaced apart slots 119 which enable the gripping arms 112of the bridge crane 65 to engage the longitudinal upper frame member 23of the rack for lowering and raising each of the racks into and from thekiln 35.

After each compartment 40 of the open top kiln 35 is loaded with racks20' of fresh concrete blocks, a roll of flexible water and steamimpervious tarpaulin 120 is rolled over the top of the cover members 25to seal the compartment 40 and prevent the escape of steam from betweenthe cover member or through the slots 119 during the curing process. Thetarpaulin 120 is preferably formed from a neoprene-coated nylon fabric.Thus in the modification shown in FIG. 11, the tarpaulin 120 replacesthe seals 28 which surround the cover members 25 shown in FIGS. 7 and 8.

To cure the fresh concrete blocks loaded within the kiln 35, steam orhot oil is introduced into the conduits 60 and a predetermined quantityof 'water is supplied to the troughs 58. The heat produced by the seamor hot oil within the conduits 60 causes the water within the troughs toevaporate and produce a hot humid atmosphere in each of the compartmentsof the kiln. The compartments are maintained at the desired temperaturefor the time required to complete low pressure steam curing. After thisperiod, the hot humid air in each of the compartments is exhausted byintroducing a supply of fresh air through the inlet manifold 45 from theblower 48. The hot humid air is thereby exhausted through the manifold50 to the outside so that when the racks 20 or 20' are removed, none ofthe hot humid air escapes into the working space directly above thekiln.

From the drawings and the above description, it can be seen thatapparatus constructed in accordance with the invention providesdesirable features for curing and bandling concrete blocks. Basically,it has been determined that the construction of the open top kiln 35substantially reduces the construction cost of the kiln when compared tothe conventional oven or tunnel-type kilns. Since the kiln is preferablyrecessed below ground level, heat loss is also reduced. Furthermore, thecombination of the open top kiln 35 along with racks each carrying acover member and a bridge crane adapted to transport each rack from thekiln to the racking machine 18, provides for a simplified and efiicientmethod of handling the blocks from the rack loading portion of theracking machine 18 to the curing kiln 35 and then back to the unloadingportion of the racking machine. The compartmentalized construction ofthe kiln 35 also enables the compartments to be used separately. Thusblocks may be cured in one compartment wile loading or unloading anothercompartment.

Another important advantage of the apparatus of the invention is thateach movement of the bridge crane 65 may be easily controlledautomatically, as for example, from a tape control system programmedwith the necessary information for successively transporting each rackfrom the kiln 35 to the racking machine .18 for automatic unloading ofcured blocks and transporting a rack loaded with fresh blocks back tothe kiln. It has been determined, however, that even without anautomatic control system, the apparatus substantially simplifies thehandling and curing of the blocks.

Another desirable feature of the apparatus of the invention is thehandling of each palletized cube of blocks as received on the platformcars 88. That is, the combination of the storage rack 95 (FIGS. 9 and10) and the bridge crane 100, enables each palletized cube to be removedfrom its corresponding car 88 and deposited into the storage rack at oneof the levels or tiers defined by the supporting rollers 98 and therebyenable the blocks to be easily and conveniently removed from theopposite side of the storage rack as the blocks are loaded for shipment.Furthermore, by controlling each movement of the bridge crane 100 with aprogrammed magnetic or punched tape, each cube of palletized blocks canbe automatically loaded onto the receiving side of the storage rackwithout employing an operator.

Thus it becomes apparent that by employing the apparatus of the presentinvention in conjunction with commercially available automatic blockforming and racking machines together with an automatic pallet unloaderand cubing machine, fresh concrete blocks can be formed, cured anddelivered in the form of palletized cubes to the storage rack 95 withoptimum efficiency and minimum labor cost. Furthermore, the apparatus ofthe invention enables the blocks to be automatically orsemiautomatically processed with a minimum capital investment forequipment. For example, the open top kiln is much less expensive toconstruct than a tunnel-type kiln, consumes less space, and the bridgecranes 65 and may be installed with substantially less investment thanwould be required for suitable fork-lift trucks capable of handling thesame production of blocks. In addition, the apparatus can 'be installedin substantially less space. That is, no floor space is required formaneuvering forklift trucks or for storing racks either before or afterthe loading and unloading of blocks into the racks.

While the form of apparatus and process herein described constitutepreferred embodiments of the invention, it is to be understood that theinvention is not limited to these precise forms of apparatus andprocess, and that changes may be made therein without departing from thescope of the invention which is defined in the appended claims.

What is claimed is:

1. Apparatus for efficiently handling and curing concrete blocks formedin successive batches on a series of pallets, comprising a kilnincluding a floor and side walls defining an open top chamber, means forintroducing steam into said chamber, a plurality of separate rackswithin said chamber and arranged in horizontally spaced relation, eachsaid rack being independently removable from said chamber, removable topcover means for said kiln, means for loading pallets of blocks into eachsaid rack, means for unloading the pallets of blocks from each saidrack, means for transporting each said rack between said loading meansand said kiln and between said kiln and said unloading means, and saidtransporting means including a vertically extendable rack engagingmember for lowering each said rack into said chamber for curing of theblocks thereon and for raising each rack from said chamber after curing.

2. Apparatus as defined in claim 1 wherein said transporting meanscomprises a bridge crane, horizontally extending track means supportingsaid crane, and said Vertically extendable rack engaging member includesrigid guide means connected to said crane for maintaining positiveorientation of each said rack relative to said crane.

3. Apparatus as defined in claim 1 wherein said removable top covermeans for said kiln includes a top cover member on each said rack, saidtop cover members disposed in generally coplanar relationship when saidracks are in said kiln for cooperatively forming a top cover for saidkiln, and means for sealing said cover members to avoid the escape ofsteam between said cover members during curing of the blocks.

4. Apparatus as defined in claim 3 wherein said sealing means includes aflexible tarpaulin extending over said cover members and adapted to berolled up during moving of said racks into and out of said kiln.

5. Apparatus as defined in claim 3 wherein said sealing means includes aresilient sealing member extending around the periphery of each saidcover member.

6. Apparatus as defined in claim 1 including at least one verticallyextending intermediate wall within said kiln for separating said kilninto a plurality of open top compartments, air vent means for each saidcompartment, and said means for introducing steam into said kilnincludes separately controllable means for introducing steam into saidcompartments to provide for curing blocks in a portion of said kiln.

7. Apparatus as defined in claim 1 including means for cubing curedblocks on a pallet, a storage rack having a receiving side and adischarge side and including means for supporting a plurality of tiersof pallets of cured blocks, means for loading said pallets of blocksinto each said layer of said storage rack, and means for transportingeach said pallet of blocks from said cubing means to said loading meansfor said storage rack.

8. Apparatus as defined in claim 7 wherein said supporting means on saidstorage rack for each tier includes a series of aligned rollers arrangedin sloping relationship towards said discharge side of said storagerack, said loading means for said storage rack including an overheadbridge crane, said transporting means including an endless trackextending from said cubing means to said storage rack, a plurality ofpower driven cars each including means for supporting a pallet of cubedblocks, and each car including means for engaging said track fordirecting said car from said cubing means to said bridge crane and thenback to said cubing means.

9. An improved method for efficiently handling and curing concreteblocks formed in successive batches on a series of pallets, comprisingthe steps of loading said pallets having blocks thereon onto a pluralityof racks, transporting each said rack by lifting and carrying said rackwith a crane to a kiln having an open top, lowering each said rack bysaid crane down into said kiln and arranging said racks in horizontallyspaced relation within said kiln to permit independent removal of eachsaid rack from said kiln, covering said kiln, introducing steam intosaid kiln for curing said blocks, lifting each said rack from said kilnby said crane after the blocks are cured, and transporting each saidrack by said crane rack unloading means.

10. A method as defined in claim 9 wherein each said rack includes acover member mounted thereon, and including the step of placing aflexible tarpaulin over said cover members to prevent steam fromescaping from between said cover members.

11. A method as defined in claim 9 including the steps of separating thepallet from each batch of cured blocks, stacking and cubing the blockson wooden pallets, successively transporting the pallets of stackedblocks on independently driven cars to a gravity discharge storage rack,and successively loading the pallets of stacked blocks into said storagerack with an overhead crane.

12. A kiln for use in the curing of newly manufactured concrete blockscomprising a substantially water impervious floor and side wallsdefining a generally rectan ular chamber having an open top, means forintroducing heat into said chamber, a plurality of substantiallyidentical separate racks positioned within said chamher and arranged inhorizontally spaced relation, each said rack having means for supportinga plurality of newly made concrete blocks and being independentlyremovable from said kiln, and means forming a substantially steamimpervious removable cover for said chamber when said racks are in placetherein.

13. The concrete block curing kiln of claim 12 in which said cover meanscomprises individual cover segments carried substantially at the top ofeach of said racks which align in substantially coplanar position witheach other when said racks are in place in said kiln.

14. The concrete curing kiln of claim 12 in which said cover meanscomprises a plurality of generally rectangular and substantially rigidcover members arranged in substantially coplanar relation.

15. The concrete curing kiln of claim 12 including at least oneintermediate vertical wall within said chamber for dividing said kilninto a plurality of open top compartments and a plurality ofhorizontally spaced racks in each said compartment.

16. A storage rack for a plurality of pallets each having a group ofconcrete blocks thereon, comprising a plurality of generally parallelspaced vertical posts arranged in a plurality of rows, adjacent saidposts spaced apart to receive a pallet of blocks therebetween, androller means connected to said posts and arranged in vertically spacedrelationship for supporting corresponding tiers of pallets having blocksthereon.

17. A rack as defined in claim 16 wherein said roller means connected tosaid posts for supporting each said tier of pallets are arranged insloping relationship to provide for gravity movement of the pallets ofblocks towards one side of said rack.

18. Apparatus for curing concrete blocks comprising a pit-like kilnhaving side walls and a bottom defining an open top chamber, rack meansreceived in said kiln through said open top for supporting a pluralityof concrete blocks for curing, trough means in said kiln bottom forreceiving a quantity of Water for vaporizing into steam during curing,means in said trough means for vaporizing said water, vent means in oneof said walls for admitting air into said kiln, and insulating means forcovering said open top chamber with said rack means in place forpreventing the escape of steam therefrom during curing.

19. Apparatus of claim 18 further comprising partitions in said kilndividing said kiln into a plurality of separate curing chambers, andsaid insulating means comprising a separate forming cover for each ofsaid chambers.

20. The apparatus of claim 18 in which said insulating means comprisesrigid sheet material.

References Cited UNITED STATES PATENTS 1,407,193 2/1922 Diescher 18-4 X1,482,187 1/1924 Hatch 252 2,990,069 6/1961 Repasky et al 252 X3,325,870 6/1967 Lacy et al 252 FREDERICK L. MATTESON, JR., PrimaryExamin r.

E. G. FAVORS, Assistant Examiner.

US. Cl. X.R.

